The present invention relates to a storage system for storing data, and more particularly, to a technique of reducing power consumption of the storage system.
A temporary work file used by a user program, which is run in a host computer, is in some cases allocated to a storage area provided by a storage system. A logical volume to be allocated to the temporary file is chosen by a job management function, and a technique has been disclosed which picks up a logical volume whose performance matches the priority level of the user program (see JP 07-84840 A). The technique disclosed in JP 07-84840 A includes a method of selecting which one of logical volumes is to store the temporary file based on the free area or input/output load of the logical volumes and a method of choosing a logical volume that has the least input/output load.
Technology for reducing power consumption in storage systems has also been disclosed, which is called massive arrays of idle disks (MAID). MAID involves stopping the spinning of, or cutting power supply to, an inactive disk drive in order to reduce electric power consumed by control circuits of disk drives and electric power used in dissipating heat that is generated by disk drives.
In the method of allocating a logical volume as a temporary file area according to JP 07-84840 A, the temporary file area allocation takes into account the program's processing efficiency or the capacity of logical volumes but not the amount of power consumed. If the temporary file is broken up into pieces to be dispersed among many disk drives in consideration solely for the processing efficiency, MAID does not function effectively in the storage system and fails to prevent a large number of powered or spinning disk drives from increasing power consumption. On the other hand, ensuring that MAID functions effectively by localizing the temporary file to fewer disk drives lowers the processing efficiency.